Absorption refrigeration



Patented May 1936 UNITED STATES 2,040,894 ansoar'rron m-zm'lcma'rronGlenn F. Zellhoefer, mm, 111.

Application December 11, 1934, Serial No. 756,979 I No Drawing.

. This present invention relates generally to a solvent material and arefrigerant mixture for absorption refrigerating machines, bothof thetwo-fluid type and of the three-fluid type.

In absorption refrigeration there is required a solvent material adaptedto remain liquid throughout the operation of the apparatus, and

a refrigerant material adapted to have a liquid and a vapor phase in thecycles of operation, adapted to be dissolved or absorbed in the solvent,

adapted to be evaporated or boiled as a vapor.

from the solvent mixture and from the solvent, and adapted to becondensed from the vapor to a liquid. Numerous refrigerants and numeroussolvents are known, as well as successful combinations of these.

The two-fluid absorption machines have certain mechanical parts whichmay be omitted or which are not duplicated in three-fluid machines.

. In a three-fluid machine, there is in addition to the two-fluidmixture a body of inert gas which is always gas, and which does not toany substantial extent dissolve in any of the components of thetwo-fluid composition, or in mixtures thereof. v

The present invention is directed to a new solvent for absorptionrefrigeration, and to combinations thereof with refrigerants. I

A particular object of the invention is the use of ethylene glycoldiacetate as a solvent.

Another object is the use of a combination of said solvent with therefrigerant, dichloromono fluoromethane.

' Examples of the two-fluid apparatus in which the new solvent materialand the new combination maybe used is application Serial No. 651,306,filed January 12, 1933, or in my U. 8. Patent No. 1,895,698, issuedJanuary 31, 1933.

Other examples may readily be cited. and will beknowntothoseskilledinthe art.

The two-fluid apparatus above referred to, briefly described, comprisesa still in which a liquid mixture of solvent and refrigerant is heatedto distill away as a vapor the refrigerant material. a condenser whereinsaid vapor is condensed to a liquid state, an evaporator wherein theresulting liquid is vaporized at reduced pressure to producerefrigeration, and an absorber in which vapor of the refrigerantmaterial containing added heat units (acquired in the refrigeratingprocess) is again dissolved in the solvent material. Suitable heatexchanging and circulating means are included, and automatic controlsmay be provided. I

The particular characteristics of such a machine are that the stilloperates at temperatures well above normal temperatures, such forexample F.; and that the cooling unit mono'fluoromethane, which islittle known.

disclosed in my co-pending type of refrigeration apparatus operates attemperatures lower than normal,

such as from 15 to F. Various parts of the apparatus difier, in theprevailing and pressures, and both pressure and temperature determinethe physical state of the free refrig- 5 er'ant material, whethergaseous or liquid, and determine the solubility relations between therefrigerant and the solvent material. It is, therefore, very importantthat the solvent and the refrigerant materials be physically adapted foruse as individual materials incertain places and for certain functions,and that they be mutually adaptedlfor certain functions when they are incombination. Other qualities not essential to re frigeration, butpertinent to practical usage, control or limit the choice of solvent orrefrigerant,- such as odor, viscosity, heat, capacity, boiling point,freezing point, volatility, chemical stability,

in combination-with the refrigerant, dichloro- The. new solvent isherein named as ethylene glycol diacetate. However in order to leave nodoubtas to its identity, its structural formula is herein given:

cmcoocrnc'mococn:

The refrigerant herein specified is dichloromonofluoromethane, However,in order to leave no doubt as to its identity, its structural formula ishereingiven: 35

. v CHChF In the accompanying claims, the invention is set forth as acombination useful in absorption refrigeration. It is to be understoodthat a'simple adulteration of the new solvent in its pure form, eitherby reason of commercial impurities, or by addition of lesser quantitiesof other material, useful-also as-solventy is permitted, and; suchacomposition is intended to fall within the scope of the presentinvention- The solvent herein specifically claimed is coveredgenerically in applicant's co-pending application Serial No. 17,064,filed April 18, 1935.

What I claim is:

1. A refrigerantmixture for the absorption consisting of diacetate asthe essentially preethylene glycol dominant solvent, and a halogenderivative of an alkyl monofluoride as a refrigerant.

2. A refrigerant mixture for the absorption type of refrigerationapparatus consistin of ethylene glycol diacetate as the essentiallypredominant solvent, and dichloromonofluoromethane as a refrigerant.

GLENN EZELLHOEPB.

